Predicting a successful outcome in sacral neuromodulation testing: Are urodynamic parameters prognostic?

Abstract

To assess whether the urodynamic parameters of mean voided volume, peak detrusor overactivity (DO) pressure, bladder compliance, capacity, and volume at first detrusor overactivity during filling cystometry can predict a successful outcome at first stage tined lead placement (FSTLP). Ninty-nine consecutive patients with urodynamically proven idiopathic detrusor overactivity (IDO) refractory to medical treatment and opting for Sacral Nerve Stimulation (SNS), were assessed pre and post FSTLP. Data from 3-day frequency-volume charts, and patient reported (subjective) outcomes were used to assess success or failure after FSTLP. Success was defined as improvement in symptoms >50%. Binary logistic regression analysis was used to ascertain whether key parameters at filling cystometrogram were predictors for success prior to FSTLP. Binary logistic regression analysis did not demonstrate any significant relationship between the five parameters at urodynamics and outcome at FSTLP (B < 0.01, P > 0.16) for all parameters. The results from this prospective analysis on patients with IDO refractive to medical therapy referred for SNS would suggest that aside from proving DO at urodynamics as a pre-requisite for intervention as per NICE and EAU guidelines, no parameter is predictive for a successful outcome at FSTLP.